On this day: July 15

2012: The video for South Korean pop singer Psy's song "Gangnam Style" debuts on YouTube. The video would eventually become the first on YouTube to exceed 1 billion views, spawning parodies and a dance craze imitating Psy's often humorous and bizarre choreography along the way.

Jerusalem falls to the Crusaders, the Rosetta Stone is uncovered, Napoleon surrenders, the Nintendo Entertainment System debuts in Japan, and Psy unleashes "Gangnam Style" on the Internet, all on this day.